Posted : August 19, 2018 By : Hope Epert

The following content is taken directly from the Research Article: Isolation and Characterization of NP-POL Nonapeptide for Possible Therapeutic Use in Parkinson’s Disease

I have tried to take out a majority of the super scientific, hard to understand jargon to make this article as easy to read as possible, without changing any of the information. To read the full article click here

1. Introduction

Parkinson’s disease (PD) is considered the second most common neurodegenerative disease after Alzheimer’s disease. PD results from the progressive loss of dopaminergic neurons in the parts of the brain that control muscle movement—the basal ganglia and the extrapyramidal area.

Clinically, PD is characterized by motor symptoms (such as bradykinesia, hypokinesia, cogwheel rigidity, resting tremor, and postural instability), sleep disorders, hyposomnia, anxiety, and depression [3].

Although the etiology of Parkinson’s disease is still not completely clear, some cases have been found, including neuro inflammation, genetic mutation of genes, and mitochondrial and proteasomal dysfunction, as well as α-synuclein aggregation [1, 2].

Several studies have reported that the overproduction of free oxygen radicals and an impaired antioxidative defense system are initial steps in PD [4,5]. Oxidative stress is a product of an imbalance between oxidative and antioxidative systems in cells, generating increased levels of free oxygen and nitrogen radicals, leading to impairment in proteins, lipids, and DNA, as well as mitochondrial dysfunction [6, 7].

High levels of redox active metals, decreased activity of antioxidant enzymes, and reduced level of glutathione play a pivotal role in the etiology of PD [8, 9].

6-Hydroxydopamine (6-OHDA) detected in both rat and human brains after long-term L-3,4-dihydroxyphenylalanine (L-DOPA) administration has also been proposed as a neurotoxin in the pathogenesis of PD [12, 13]. 6-OHDA acts via inducing reactive oxygen species (ROS) overproduction and energy depletion [13–15].

The toxic effect of 6-OHDA results from the overproduction of ROS through three pathways: extracellular auto oxidation, intracellular metabolism, and direct inhibition of the mitochondrial respiratory chain.

The increase in the level of ROS by 6-OHDA leads to a decrease in cellular antioxidant enzymes and, subsequently, neuronal apoptosis [16].

The treatment of PD has not changed substantially in the past 30 years, with the key role of dopamine replacement therapy, including L-3,4-dihydroxyphenylalanine(L-DOPA) and dopamine agonists, supported by the use of peripheral decarboxylase inhibitors, catechol-O-methyl transferase inhibitors, and monoamine oxidase-B (MAO-B) inhibitors [17].

The current treatments do not prevent the continuing loss of dopamine neurons, and eventually, treatment-related side effects result in severe disability.

One viable alternative to the drugs used in treating PD can be natural products—nutraceuticals or functional foods—commonly used for preventing or attenuating the process of aging. The strong therapeutic potential of bioactive compounds obtained from natural products in age-related disorders such as Parkinson’s disease is associated with their multidirectional action. They are more available and considerably safer to use and can promote pro survival signals and act as antioxidants [18, 19].

These substances can act as agonists for dopaminergic neurons, improve cognitive function, promote mitochondrial function, inhibit ROS generation, and also possess immunomodulatory activity [20, 21].

An example of such a compound is the previously unknown nonapeptide NP-POL isolated as a component of the proline-rich polypeptide complex (PRP, also known as Colostrinin).

PRP is a complex of low-molecular weight peptides ranging from 500Da to 3000Da, first isolated from ovine colostrum, and also present in human, bovine, and caprine colostrum [22]. It is one of the many important constituents of colostrum, the first mammalian nourishment, which may stimulate the neonate immune system and play a regulatory role in newborn development, next to immunoglobulins, cytokines, and lymphokines.

It is active both in vivo and in vitro and is not cytotoxic even at 1.25g/kg body weight. Because of its multicomponent character, PRP shows pleiotropic activity. It has immune regulatory properties, regulating both humoral and cellular immune responses. It modulates the innate immune response, including phagocytosis and the balance between oxidants and antioxidants, thus regulating redox-sensitive cellular signaling [23–25].

Additionally, PRP can affect learning, memory, and lifespan and possesses neuroprotective activity [23,26,27]. The activity of PRP suggests a potential therapeutic use in the case of diseases associated with changes in innate immunity, for example, Alzheimer’s disease [23].

It has also been suggested that PRP has potential in treating other neurodegenerative diseases, such as multiple sclerosis, Parkinson’s disease, and amyotrophic lateral sclerosis.

The present study shows a method of isolation and purification of a previously unknown PRP constituent, NP-POL nonapeptide. In addition, we used the PC12 Tet On cell line to investigate the protective effect of NP-POL in 6-OHDAinduced oxidative stress.

Our study provides new evidence that NP-POL may protect PC12 cells against 6-OHDA cytotoxicity through a neuroprotective and antioxidant activity. Our results indicate a potential use of NP-POL in the therapy of Parkinson’s disease.

2. Materials and Methods

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3. Results and Discussion

Colostrum and milk are the initial mammalian nourishment. They are the richest reservoir of important nutrients in newborn development. They contain protective and supporting factors, such as immunoglobulins, cytokines, and also lymphokines and peptides which may stimulate the neonate immune system and play a regulatory role [36, 37].

One of the misaproline-rich polypeptide complex (PRP) from ovine colostrum, also known as Colostrinin (CLN). PRP was first discovered over 30 years ago as an IgG2-PRP complex and was subsequently found in human, bovine, and caprine colostra [22].

The immunomodulatory activity of PRP suggests a therapeutic use in the case of diseases in which changes in innate immunity play a role, including neurodegenerative disorders [23].

The current study presents a method of isolation of a previously unknown NP-POL peptide from PRP and shows its potential biological role in the regulation of cellular mechanisms regulating the survival of nerve cells treated with neurotoxic 6-hydroxydopamine and its potential use as a pharmacological preparation in the treatment of Parkinson’s disease.